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Brezzasoft Crystal System conversions

ack said:
This is what I see on my dongul pic with a logic probe /multimeter

01 <=> dead
02 <=> dead
03 <=> dead
04 <=> Pulse a little after boot then goes LOW / PIN 116 on Vrender0
05 <=> LOW / GND
06 <=> dead
07 <=> dead
08 <=> dead
09 <=> dead
10 <=> dead
11 <=> dead
12 <=> dead
13 <=> dead
14 <=> HIGH / VCC (3.5V measured)
15 <=> LOW / clock? 100ohm between pin and upper clock pin
16 <=> dead
17 <=> Pulse a little after boot then goes LOW / PIN 113 on VRender0
18 <=> dead
Click to expand...
Pin 4 seems to be /MCLR = Master Clear = Reset on most PIC datasheets I've seen.
Pin 17 is RA0 = bit 0 of port A
Pin 15 is OSC2/CLKOUT
(Pin 16 should be OSC1/CLKIN)

These pins are actually identical on many PIC variants of that package size, the differences are in amount of Program FLASH, RAM and peripherals.

Of course, if the main cpu just boots whatever it has got if the PIC is not found then we can use brizzo's information to build a cart around pre-patched games. :)

Another problem will be memory chips: The original cartridges use Intel E28F128J3A (128 MBit, 16MB) 3V Flash chips which don't seem to be in stock at big distributors. You can get them for silly prices on eBay, or from smaller resellers on dodgy websites. There are bigger flash chips available from other vendors, but someone will have to dig out the datasheets and see what is usable.
 
@Fluffy your analysis of the PIC pint is correct. Two signals are connected for reset and serial data

Last night I took a closer look at the PIC dumps and they are not entirely correct. The PICs from 'Top Blade V' and 'Office Yeo In Cheon' were dumped by Dr.Decap in 2010. When you decap and optically inspect PIC microcontrollers, there are not clear markings that indicate the exact part number being used, so this can lead to over dumps (which I think is the case for both), meaning there is extra crap data at the end of the binary file in MAME. For example the pic dump for 'Top Blade V' is labeled as PIC16C727, but it was never available as an 18 pin device.

Fluffy said:
Another problem will be memory chips
Click to expand...
Only a problem if people want to attempt converting or using original cartridges --- which I do not recommend. But I will mention it is possible to re-program a cartridge from the cartridge edge connector. On the back of the cart position R2/R3 has a 0 ohm resistor, R2 = write enabled, R3 = write protected. The rest of the data/address bus and required signals are exposed for programming.

Lots of options for modern 3.3v 16bit parallel nor flash in 128/256/512/1024 mbit sizes.

Found the box of crystal system hardware, and located files with research notes, pcb scans and cartridge schematics
 
@brizzo - I know the system is really niche, and I also know that you’re a very busy person, but would you ever explore creating a multi for the people who own the system?
 
twistedsymphony said:
damn, with one of those larger sizes and the small number of games you could probably build a multi from a single flash chip.
Click to expand...
Indeed, that was my thought too. Only tough part is deciding what and how many games should fit and obeying 'keep it simple stupid'.

djsheep said:
@brizzo - I know the system is really niche, and I also know that you’re a very busy person, but would you ever explore creating a multi for the people who own the system?
Click to expand...
I had never considered it before because it was so niche, honestly surprised how many people actually have one in the few days this thread has been up. Compared to other multis, this is a walk in the park to build. Given it only has one data/address bus and option for single flash chip, it would be straight forward to re-use the software library I created for the sys2x6 dongle (its similar in the sense that its a single flash chip pcb).

How do you guys imagine this would work? What price point makes sense? The more capacity and switching, the more it costs. (large capacity parallel nor flash is relatively expensive)

Would a usb programmable cartridge that supports 1 game of any size do the job?
 
A US seller recently came out and sold nearly every game on the system, this is probably why there's renewed interest. I already have Crystal of Kings which is the best game on the sytem, but I wouldn't shy away from having the rest of the games (are there any unreleased games you unearthed @brizzo ?).

I guess the simpler the better given the limited library. A USB programmable cart would do just fine... but what would it cost to get all the games on a chip/cart with a simple way to select them?
 
brizzo said:
How do you guys imagine this would work? What price point makes sense?
Click to expand...
I don't own one of these (yet :D) but IMO the ideal setup would be:
1. an easy way to flash all of the games to the cart at once. Maybe there is a USB port (like the dongle) to flash it? maybe it has pins in a DIP layout so you can insert the cart directly into a EPROM programmer?

2. dip switches, or a rotary selector switch to change games.

3. a form factor so that you could fit it in an original cart case (without trimming the case) if you wanted.

Assuming the games are patched without the need for the PIC this should really just be a PCB with flash ROM(s) large enough to fit the entire game catalog, the selection and programming should be as cheap as possible to keep costs and complexity low.
 
brizzo said:
How do you guys imagine this would work? What price point makes sense? The more capacity and switching, the more it costs. (large capacity parallel nor flash is relatively expensive)
Click to expand...
I imagined a block of jumpers or dip-switches, and a pal to offset the top bits of the base address/chip select for the different games.

I didn't plan to manufacture them, I would just release the schematic/gerber files so people can order them from a pcb manufacturer of their choice.
Would a usb programmable cartridge that supports 1 game of any size do the job?
Click to expand...
For the small number of games I feel this would be overkill... MAYBE if you could get the motherboard to program the cart itself, but then you'd have the problem of getting the game data into the system (and programming an exotic RISC architecture...)

(By the way, am I the only one who thinks "Brezzasoft" could be the name of a small 80's UK publisher for ZX Spectrum games?)

I think it would still be worth to identify the PIC used, so people can resurrect carts in the future if the chip fails.
 
djsheep said:
are there any unreleased games you unearthed @brizzo
Click to expand...
I was sent three undumped cartridges by the dumping union (I believe two are games, one is a redemption machine). They aren't anything too exciting, forgot I had these to dump -- but rediscovered them when I opened box of crystal system hw. I don't have the correct tsop56 adapter for J3 chips (they are unique), but I did order one last night and should be here in a week or two. Two of the cartridges do not have or use a PIC, so that is how I can suggest no-pic is an option.

djsheep said:
what would it cost to get all the games on a chip/cart with a simple way to select them?
Click to expand...
Perhaps the best option is a cartridge with 2x1024mbit flash, which would allow for 4 games up to 512mbit per game (each chip on an original cartridge is 128mbit, never seen a cart with more than 4)
 
That all sounds great @brizzo — keen to see any progress you make. No rush whatsoever.

How many games in total are there for the system?
 
djsheep said:
That all sounds great @brizzo — keen to see any progress you make. No rush whatsoever.

How many games in total are there for the system?
Click to expand...
With Brizzo's undumped trio that puts us at 7, doesn't it?

The PCB would have to keep the notches to lock it in place for those of us without cart shells /90 degree risers.
 
The 5 games released on the system are:
Donggul Donggul Haerong
Evolution Soccer (cart)
Office Yeo In Cheon Ha
The Crystal Of Kings (cart)
Top Blade V


+ the 3 that Brizzo has, which brings it to 8!
 
I think what brizzo said is good advice, to look for chips in production with larger size. Someone will have to look at the datasheet and verify the speed/timing is compatible, though.
 
It sounds nice to have all games at the ready playable with a flick of a switch, but at least in my opinion some are of zero interest to play. It is not only additional parts cost for more flash capacity, but also time to route additional pcb parts and assembly.

Wuly Buly - Crystal System Hardware
https://www.youtube.com/watch?v=iRGz1wxtlms

Urachacha Mudaeri - Crystal System Hardware
https://www.youtube.com/watch?v=xYJ0Jqk11mU
 
I am on the opposite end of that. If we're to do it at all, why not do it 100%. Even if they're lame, they're part of the weird world of Crystal System.

I guess knowing what kind of price difference you're talking about would be helpful in terms of determining the value in having them all available?
 
Quick and dirty outline and connector:
brezzasoft.jpg


... based on a scanned picture, so most likely miles off. Though if someone gives me proper measurements I can plug them in.

If someone wants to compare it against a real cartridge I attached a pdf to print out. I made no effort to align the connector with the outline, or to add the double-wide pins for power.

Edit: By the way, the spacing looks a bit like PCI. Do these cartridges fit into a classic (3.3V) PCI slot? (I mean physically, not electrically! Don't switch on a system like that!)
 

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